His interview with the Boston Globe appeared in the Sunday Magazine over the weekend. Among his quotes/observations:

“Social isolation has an impact on health comparable to the effect of high blood pressure, lack of exercise, obesity, or smoking,”

Loneliness is not simply a matter of being alone. The lonely often spend as much time with others as the less lonely. The key difference is that the lonely have the feeling that any real connection with others is lacking.

Loneliness is half heritable and half environmental, but the heritable part seems to be associated with how much disconnection hurts.

“In 1984, the question was asked [in the GSS survey], ‘How many confidants do you have?’ And the most frequent answer was three. That question was repeated 20 years later, in 2004, and the most frequent response was zero.”

Cacioppo and Patrick highlight some interesting experiments among the lonely, among them:

That faced with a task of trying enough cookies to rate their flavor, on average, people who have been told that co-workers didn’t like working with them ate twice as many cookies as people who had been told that co-workers loved working with them.

Those who are lonely, for example in playing the Ultimatum Game, settle for far worse outcomes or distributions than those who are not lonely (similar to people with low self-esteem choosing partners or dates who mistreat them, subconsciously justifying that they are not worthy of better treatment).

The lonely sleep less well and less efficiently.

The lonely can’t think as clearly.

The lonely were more likely to describe a gadget anthropomorphically and the lonely were more likely to believe in the supernatural (e.g., God, angels or miracles), and believed in the supernatural more when they were feeling lonely.

Lonely people had higher levels of chronic inflammation, a condition associated with heart and artery disease, arthritis, Alzheimer’s and other illnesses.